I had to jet it just a bit to ensure reliability..( I will check to see exactly what I am running it i now..I believe it's 140s BUT I am not sure I will find out). I have found that the pipe is louder but to too much, the performance is better ( mid,top end )..I just put the pipe on about a month a go (300kms) so far so good..My buddy helps me out with most of the work this summer I am custom making a cold air intake ( hard to find one) and reeds so I am sure i will have to re jet again with a new track it should be a great play sled..But I won't go any father then that I don't want to blow it...I know how you guys feel with the Phazer,( Venture) great sleds but you just want a little more power but don't want to ruin the fact that it is the most reliable sled on snow !!! As for clutching I am still playing with it, I don't have that worked out just yet!!!